(167h) Fabrication and characterization of green composites of agave fiber and biodegradable poly(3-hydroxybutyrate) (PHB) matrix

Poly(3-hydroxybutyrate) (PHB) is a commercially available, biodegradable thermoplastic produced via bacterial fermentation. PHB is a sustainable polymer, however it is extremely brittle and has a narrow melt processing window as compared to commercial polyolefins. Natural reinforcements, such as fibre, can lead to improvements in mechanical properties while simultaneously increasing the biodegradability of the polymer. Natural plant fibres have several advantages compared to traditional fibres, such as lower density, cost, and environmental impact. As such, natural fibre composites are commonly used in automotive, packaging, and household applications. This study features the use of agave fibre from the Agave Americana plant which is native to Central and North America. The biocomposites were prepared at 85:15 and 75:25 ratios of PHB and agave fiber respectively. The incorporation of an organic peroxide initiator into the PHB agave composites enhanced the fiber matrix adhesion and hence improved the compatibility. The Soxhlet extraction of composites were conducted to find out the grafting efficiency of PHB on agave fiber. Interestingly, the grafting percentage of compatibilized composites was increased by ~25% compared to the uncompatibilized composites. It was found that the reactive extrusion of agave PHB composites with 0.1phr to the 75/25 composite increased the flexural and impact strength by ~45% above pristine PHB. The improved fibre-matrix adhesion of the peroxide treated composite was confirmed using morphological analysis. Overall, PHB with 25 wt% agave fiber and 0.1phr of organic peroxide presents a promising composite for use as a sustainable material for automotive and packaging applications.

Acknowledgments

The authors acknowledge the financial support of the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA), Canada/University of Guelph - Bioeconomy for Industrial Uses Research Program (Project # 030177 and 030486); the Ontario Ministry of Economic Development, Job Creation and Trade, Canada Ontario Research Fund Research Excellence (ORF-RE 09-078) (Project #053970 and 054345); and the Natural Sciences and Engineering Research Council (NSERC), Canada Discovery Grants Project # 400320.